So, say, you are playing some of the Bro-op I came upon this idea. The doppelgangers are basically enemy bros (color-switched ones?) or clone bros (a character being the reskin of another one).How would it work?

Well, the game has its fair share of mayhem already, Doppelgangers would either help focus the mayhem (Two mcbrovers, brominators, brommandos, or any other bro thats actually destructive), or to make a bossfight/lategame enemy/horde (basically better terrorists).

i dont get what you are suggesting. Are you now suggesting, that two players can play the same bro at the same time?Or are you suggesting a bossfight against Twins (so 2 Bosses at once)?Or do you suggest to fight a copy of yourself in a bossfight (so you play Rambro so you fight Rambros clone)?And another question, i know the german word is Doppelgänger, is the english word really doppelganger? :o) I know some english words are taken from the german language,like rucksack or kindergarden. Do you really use your word in english too? Would be interesting for me to know.

Mainly yes, you get clone bros (Same skillset, different sprite) and evil bros (Which come in all combinations and numbers possible) for augmented mayhem and maximum steambrolling.

I have no knowledge about the english word etymology, so I can't really give an answer, but it is usually used to refer to an evil copy of something (like bros and stuff). If possible these 'Doppelgängers' should be the main antagonists of their respective movies or a known villain of these.

very interesting. I'm sorry, i'm studying and i'm learning english atm to improve it for working in other countries later on so i'm ever intrested in improving it.What you suggest sounds a bit like a thing that could be implemented in the Multiplayer Competitive Mode (Deathmatch). To fight his Doppelganger in the Story (maybe as an Evil Clone made by your enemies to kill you) could be awesome too.